This invention relates to flow cells for receiving successive fluid samples to be examined by a plurality of radiant energy measuring devices. In particular, the invention relates to a novel flow cell unit or cuvette having an especially configured bore and insertable sample receiving chamber for use with a micro-sample spectrometer or fluorometer or similar measuring device. The chamber has an axial through window and a transverse side window. The interior of the bore has smooth viewing surfaces such that optical density and fluorescence characteristics of the sample in the chamber can be accurately ascertained.
Presently, there are two conventional methods for determining optical characteristics of a plurality of small fluid samples. One such method is to place each sample in a separate container, test tube or cuvette and position the container in the flow path of a beam of light or other radiant energy provided by a spectrophotometer or flourometer. Such method is subject to uncontrollable error due to physical variations between sample containers which cause differences in optical characteristics.
The other conventional method and that employed by the fluid sample flow embodied herein involves the use of a single sampling container as set forth in U.S. Pat. Nos. 3,515,491 and 3,646,313. Unfortunately, the use of a single container is attended by its own problems including the formation of bubbles which lie in the optical path and the inability to easily detect different optical characteristics.
The improved flow cell of this invention all but obviates the above problems by the use of simplified bubble prevention techniques and a multi-purpose viewing system.